1数组中删除重复 let arr = [1,2,4,3,6,4] Array.from(new Set(arr)) // es6中 .from()[1,2,4,3,6] [...new Set(arr)] // 扩展运算符[1,2,4,3,6] 2替换数组中指定的值 arr .splice(1,3,7,8,9) // [7, 8, 9] arr // [1, 7, 8, 9, 6, 4] 3数组映射 let mapValue = [ { name: '山东', value: 22 }, { na…